Due to its highly addictive nature, the street drug crystal meth (methamphetamine; also known as "ice," "crank" and "Tina") has become a threat to the health of some people at risk for or who have HIV. Before delving into research on recovering from crystal meth, we first provide some background about the effects of this drug, some of which may be surprising.

How Did This Happen?

Smoking, snorting or injecting crystal meth can result in a prolonged and intense high. Many users initially report feelings of euphoria, increased energy, alertness, heightened awareness, reduced appetite and enhanced sexual pleasure. All of these effects can make self-medicating with crystal meth an alluring possibility for some people who have the following problems:

  • lack of energy
  • low self-confidence
  • anxiety
  • difficulty sleeping
  • problems concentrating
  • feelings of worthlessness
  • being depressed
  • being overweight

Researchers in San Diego have been conducting research with people who use crystal meth. In one of their early studies with 25 HIV positive men, the men gave the following reasons for using crystal meth:

  • it provided a temporary escape from being HIV positive
  • it helped manage negative self-perception and social rejection associated with being HIV positive
  • it made it easier to approach sexual partners and to have anonymous sex with multiple partners
  • it was a method of coping with the spectre of death

More, More, More

The use of crystal meth is associated with more frequent sexual activity, sex with more partners and an increased risk of unprotected sex as users lose themselves in the drug's effects. All of these increase the risk of transmitting HIV.

The Challenge of Recovery

There is no simple remedy for breaking free from the addiction of crystal meth. Most distressingly, people who become addicted to this drug appear to have little insight into the fact that the drug has become the focus of their lives.

Crystal and the Heart

The heart helps to push blood around the body because this organ is a muscular pump. Crystal meth speeds up the pumping action of the heart and raises blood pressure. Both of these effects strain the heart and blood vessels.

As the heart beats faster and for prolonged periods because of crystal meth, it requires more oxygen. But this drug can shrink the size of arteries, which transport oxygen-rich blood to the heart. A heart that's forced to pump faster without enough oxygen can become damaged. Crystal meth can also increase the chance of blood clots spontaneously forming. If sufficient clots appear and begin to stick together, they can block blood vessels. As a result of all of these negative cardiovascular effects, sometimes crystal meth users can develop chest pain, rapid heart beats and, in some cases, heart attacks and stroke. Although these extreme results are not common in the short term, the effect of repeated use of crystal meth is to pave the way for future heart disease.

Meth and the Brain

In additional to cardiovascular stress, crystal meth can cause strange changes in a person's behaviour and ability to think clearly and rationally, as outlined below.


Users of crystal meth can experience temporary -- lasting hours or days -- delusions and hallucinations and, less commonly, incoherent speech. Delusions often involve feelings of being persecuted. As a result, people experiencing crystal meth-related psychosis can become agitated, emotionally unstable and even hostile.

Users who have pre-existing schizophrenia, mania or psychosis are at high risk for having these underlying disorders become active. However, most crystal meth users who have experienced psychosis do not appear to have a history of this or related disorders.

Depressive Illness

Symptoms of depression and anxiety seem to be higher than normal in crystal meth users both before and after using this drug. Depression in crystal meth users can have fatal consequences. In one study, Australian researchers found that about 50% of crystal meth users reported feelings of anxiety before they used this drug. Afterwards, when the drug's effects had worn off, 75% reported experiencing severe symptoms of anxiety.

Also in Australia, researchers found that about 33% of crystal meth users were diagnosed with depression either before or after exposure to this drug. And about 25% of Australian stimulant users (crystal meth, cocaine and similar substances) have attempted suicide at some point in their lives. This compares with a figure of about 5% in Australians who have not used stimulants. Overall, these findings in crystal meth users point to a need for mental health services.


The link between crystal meth and violence is controversial, with some researchers disputing it. Still, it is possible that there is a link because of the following:

  • Repeated exposure to crystal meth seems to increase aggressive behaviour.
  • People who use crystal meth can become aggressive if they perceive that they are threatened.
  • Crystal meth can provoke episodes of psychosis, which, in some cases, can lead to aggressive behaviour. Australian researchers have found that some crystal meth users can have high rates of pre-existing behavioural issues, which may be made worse by exposure to crystal meth. So it is possible that crystal meth simply unmasks pre-existing tendencies in some people rather than directly causing some users to be violent. The link between crystal meth and violence continues to be studied as researchers try to learn more about the many effects of this drug.

Brain Damage

Studies in mice and monkeys have found that crystal meth can cause parts of their brains to become depleted of neurotransmitters, compounds used by brain cells to communicate. Low levels of neurotransmitters can cause brain cells to become dysfunctional and have been linked to depression, anxiety and other disorders.

In lab experiments with cells, exposure to crystal meth seems to enhance HIV's ability to damage brain cells. This drug also appears to trigger inflammation in the brains of monkeys. Over the long term, such inflammation may have negative consequences.

Researchers are less certain about any physical brain damage that crystal meth might cause in people. Still, it is very clear that the use of this drug is associated with a broad range of harms.

Trying to Recover

A challenge to helping crystal meth addicts recover is that this drug appears to diminish their capacity to have insight into their condition. Moreover, withdrawal symptoms in people trying to quit crystal meth are unpleasant and can include the following:

  • a profound lack of energy
  • difficulty falling asleep
  • irritability
  • changes in appetite
  • loss of interest in regular everyday activities
  • anxiety
  • depression
  • an intense craving for crystal meth

Another challenge is that some scientists suspect that "the 'memories' of addiction might be 'hard-wired' and involve actual structural changes to brain [cells] that make addiction resistant to [treatment]."

A Bit About Terms

Amphetamine and methamphetamine are two very closely related chemicals with similar effects, although amphetamine is less powerful. In the body, methamphetamine is partially converted into amphetamine. More about amphetamine appears in the next CATIE News story.

The Good News

The complex interaction between methamphetamine and the brain is not fully understood. But this has not stopped scientists from trying to find ways to help people exposed to crystal meth recover and stay in recovery. Indeed, based on animal experiments and autopsies of the brains of meth users, scientists are beginning to better understand how the brain and crystal meth interact. As a result of this research, some scientists have found that the drug naltrexone, used to treat heroin addiction, can partially reduce the craving for amphetamine and methamphetamine in addicted people. This suggests that when the brain is exposed to amphetamine (and closely related compounds such as crystal meth), it produces a natural opiate.

Swedish Success

Scientists in Sweden have been testing the anti-addiction medication naltrexone in people addicted to amphetamine and methamphetamine with some success. Our next _CATIE New_s bulletin focuses on this research and brief personal accounts from two people who broke free of these drugs because of naltrexone.


  1. Urbina A, Jones K. Crystal methamphetamine, its analogues, and HIV infection: medical and psychiatric aspects of a new epidemic. Clinical Infectious Diseases. 2004 Mar 15;38(6):890-4.
  2. Koblin BA, Husnik MJ, Colfax G, et al. Risk factors for HIV infection among men who have sex with men. AIDS. 2006 Mar 21;20(5):731-9.
  3. Day JJ, Carelli RM. Methamphetamine induces chronic corticostriatal depression: too much of a bad thing. Neuron. 2008. 2008 Apr 10;58(1):6-7.
  4. Bamford NS, Zhang H, Joyce JA, et al. Repeated exposure to methamphetamine causes long-lasting presynaptic corticostriatal depression that is renormalized with drug readministration. Neuron. 2008 Apr 10;58(1):89-103.
  5. Kaye S, McKetin R, Duflou J, et al. Methamphetamine-related fatalities in Australia: demographics, circumstances, toxicology and major organ pathology. Addiction. 2008 Aug;103(8):1353-60.
  6. Darke S, Kaye S, McKetin R, et al. Major physical and psychological harms of methamphetamine use. Drug and Alcohol Review. 2008 May;27(3):253-62.
  7. Kaye S, McKetin R, Duflou J, et al. Methamphetamine and cardiovascular pathology: a review of the evidence. Addiction. 2007 Aug;102(8):1204-11.
  8. Kish SJ. Pharmacologic mechanism of crystal meth. Canadian Medical Association Journal. 2008 Jun 17;178(13):1679-82.
  9. Kish SJ, Fitzmaurice PS, Boileau I, et al. Brain serotonin transporter in human methamphetamine users. Psychopharmacology (Berl). 2009; in press.
  10. Coutinho A, Flynn C, Burdo TH. Chronic methamphetamine induces structural changes in frontal cortex neurons and upregulates type I interferons. Journal of Neuroimmune Pharmacology. 2008 Dec;3(4):241-5.
  11. Frankel PS, Alburges ME, Bush L, et al. Brain levels of neuropeptides in human chronic methamphetamine users. Neuropharmacology. 2007 Sep;53(3):447-54.